This protocol is designed as a training study, to permit evaluation and treatment of subjects with critical illnesses. A data base, not otherwise obtainable, will be collected of disease processes related to critical illness. Observation of the short-term effects of intensive care interventions will also take place. Minimal studies scheduled for each admission will include a medical history and physical examination, monitoring of hemodynamic status, routine laboratory tests, and evaluation for possible causes of the critical illness. Treatment plans will be individualized for each patient's condition, and the number and length of additional visits and diagnostic evaluations will vary accordingly. Suitable candidates for this study could include critically ill patients with a diagnostic or therapeutic dilemma, an unusual presentation of disease, or a disease requiring novel therapy available at the CC. Because inter-hospital transfer of the critically ill may increase patient risk, patients will be accepted only if there is a likely medical benefit that outweighs the risk of transfer and if the risk of transfer is thought to be acceptable by both the referring and accepting physicians. Critically ill patients represent a vulnerable population because of serious illness that may affect their ability to make decisions. They must have an identified durable power of attorney or next-of-kin designated for decision making, prior to transfer to the CC. The risks of this study include the risk of transfer of a critically ill patient from one facility to another and the risks of standard or accepted medical care. The establishment of this protocol will provide a means to evaluate and treat patients, and to generate hypotheses and protocols based on this clinical experience in critical illness.